Related Experiment Video
Updated: Aug 18, 2026

Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Thermal activation and inactivation of melanin formation in vertebrate skins and melanomas
Abstract:
The melanogenic activity of tyrosinase as a function of temperature was studied in 9 different skin and melanoma tissues of vertebrates. The 600 times g supernatant fraction of tissue homogenates was incubated with 14C-L-tyrosine at 0 degrees to 60 degrees C for 16 hr and the 14C-melanin product was determined. The range of optimal temperature occurred at 35 degrees to 45 degrees C. The maximal activity and thermostability depended on the source of the enzyme preparation utilized. Thermal activation and species differences in the optimal temperature for maximal activity are complicated processes which depend upon many factors. At cold conditions, a higher percentage of maximal activity was achieved with enzyme from cold-blooded species than with enzyme from warm-blooded species.
Related Concept Videos
The Intrinsic Apoptotic Pathway
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
Photoreceptors and Visual Pathways

